Manifold imaging system

ABSTRACT

A manifold set of donor layer, imaging material layer and receiver layer is formed between a backing electrode and a tape electrode. The tape electrode is initially wound on a spool and is laid out over the various layers of the manifold set by unwinding it from the spool. The imaging material is exposed to electromagnetic radiation and subjected to electric field. The donor and receiver layers are separated when the tape electrode is wound back onto the spool yielding complementary images formed from the imaging material on the donor and receiver layers.

United States Patent Davidson [54] MANIFOLD IMAGING SYSTEM [72]Inventor: Jams R. Davidson, Rochester, N.Y.

[73] Assignee: Xerox Corporation, Rochester, NY.

[22] Filed: Oct. 31, 1969 [21] Appl. No.: 872,850

[ 5] Feb. 15,1972

Primary Examiner-John M. Horan Attorney-James J. Ralabate, David C.Petre and Michael H. Shanahan [57] ABSTRACT A manifold set of donorlayer, imaging material layer and receiver layer is formed between abacking electrode and a tape electrode. The tape electrode is initiallywound on a [52] spool and is laid out over the various layers of themanifold set [51] Int. Cl. ..G03g 15/00 by unwinding it from the SPOOLThe imaging material is [58] Field Of Search ..355/3, 16, i7 posed toelecuomagletic radiation and subjected 0 electric References Citedfield. The donor and receiver layers are separated when the tapeelectrode is wound back onto the spool yielding comple- UNTED STATESPATENTS mentary images fonned from the imaging material on the donor andreceiver layers. 3,393,617 7/1968 Gaynor ..355/3 12 Claims, 6 DrawingFigures PATENTEDFEB 15 I972 sum 1 or A TTORNE'V PATENTEUFEB 15 I972SHEET 2 0F 3 BACKGROUND OF THE INVENTION This invention relates toimaging systems and in particular to systems of the type wherein animage is formed by the selective transfer of a layer of imaging materialsandwiched between donor and receiver sheets.

A new imaging system herein referred to as a manifold imaging system hasbeen devised wherein an image is formed by stripping apart donor andreceiver sheets between which an imaging material resides. The imagingmaterial is divided between the donor and receiver sheets during theirseparation by virtue of preferential adhesion of the imaging material toone or the other sheet. The preferential adhesion of the imagingmaterial for the donor or receiver layer results from exposing theimaging material to electromagnetic radiation and subjecting it to anelectric field.

In general, the imaging material includes photosensitive particlesdispersed in a binder. At the time the layers are separated, the imagingmaterial is cohesively weak or structurally fracturable. By this ismeant that the cohesive force of the imaging material is less than theadhesive force of the material with either the donor or receiver sheets.In most cases, the imaging material has a stronger adhesive attractionfor the donor layer hence giving rise to the name donor sheet. After theimaging material is exposed to imagewise electromagnetic radiation andsubjected to an electric field, the adhesive attraction between theimaging material and the receiver layer is greater in areas exposed toradiation hence giving rise to the name receiver sheet. Voltagepotentials are coupled to the donor and receiver sheets when the sheetsare separated and the imaging material is divided between them yieldingpositive and negative images. The polarity of the voltages and the shapeof the electromagnetic radiation (or alternatively the shape of theelectric field) determine on which of the two sheets the positive andnegative images are formed.

. One theory proposed to explain why the imaging material is morestrongly attracted to one abutting sheet than the other is that thephotoresponsive material exposed to electromagnetic radiation, e.g.,visible light, and that not exposed to the radiation tend to move inopposite directions under the influence of the applied electric field.Since the material is fracturable at time of separation, the imagingmaterial is selectively transferred to the donor and receiver sheets incomplementary imagewise configurations. A detailed description of themanifold imaging process is found in copending application Ser. No.609,057, now abandoned.

The instant invention provides a solution for forming a manifold set ofdonor layer, imaging material and receiver layer. In addition, theinvention proposes novel means for applying afield across the manifoldset, for separating the layers of the set to obtain the desired imagesand for advancing new materials into place for formation of a subsequentmanifold set.

Accordingly, it is an object of the present invention to improvemanifold imaging systems.

Another object of this invention is to feed separate layers together toform a manifold set, to cover the manifold set with electrodes forestablishing an electric field across it, to strip apart or separate thelayers of the manifold set and to eject the processed layers from thesystem.

Yet another object of this invention is to devise novel and versatilemethods and apparatus for obtaining intimate contact between the layersof a manifold set.

Still another object of the present invention is to devise novel meansand methods for separating the layers of a manifold set.

Even a further object of the present invention is to rapidly andefficiently move webs from separate reels into intimate contact, stripthe webs apart, move one web onto another reel and cut and eject theother web.

These and other objects of the present invention are accomplished byutilizing a flat plate backing electrode and a flexible tape electrodecoiled or wound on a traveling spool. A donor web carrying the imagingmaterial is fed into position over the backing electrode. A receiver webis fed by pinch drive rollers into the nip formed between the tapeelectrode and the backing electrode. The spool on which the tapeelectrode is wound moves to unwind the tape electrode and trap thereceiver web and donor web between them forming the manifold set. As thespool travels across the backing electrode the force of the spooldirected against the tape electrode drives out the gases between the twoelectrodes creating a vacuum which brings atmospheric pressure intoplay. Atmospheric pressure acts in the same direction as the mechanicalforce of the spool and the electrical force of a field to 1 5 maintainthe various layers of the manifold set in intimate contact. The backingelectrode and donor webs are transparent to allow the imaging materialto be exposed to the actinic electromagnetic radiation in imagewiseconfiguration. A voltage potential is coupled between the backing andtape electrodes.

After exposure, the receiver web is pulled away from the donor webduring the winding of the tape electrode resulting in the formation ofcomplementary images on the receiver and donor webs. Means are providedto eject the used portions of the donor and receiver webs and to bringnew materials into place for the formation of a subsequent image.

DESCRIPTION OF THE DRAWINGS Other objects and features of the presentinvention will become apparent from a'further reading of the presentlayers during their separation;

FIG. 2 is a schematic side elevation view of the present manifoldimaging system;

FIG. 3 is a schematic illustration of the tape electrode being unwoundfrom the spool;

40 FIG. 4 is a schematic illustration of the tape electrode being woundonto its spool and the receiver web being separated from the donor web;

FIG. 5 is a cross-sectional view of the manifold set taken along thelines 5-5 in FIG. 2; and

FIG. 6 illustrates apparatus for supporting the spool on which the tapeelectrode is wound.

DESCRIPTION OF THE INVENTION FIG. 1 illustrates a manifold set 1 used inmanifold imaging systems. Manifold set 1 includes the transparentsubstrate or donor layer 2 on which is deposited the layer of imagingmaterial 3. The receiver layer 4 is brought into contact with theimaging layer to complete the formation of the manifold set. The imagingmaterial 3 comprises the photosensitive particles 5 dispersed in abinder 6. Commonly, the imaging material has good cohesive strengthprior to imaging in order to facilitate its handling and storage. Insuch cases, the cohesive strength of the imaging material is weakenedprior to formation of the manifold set by softening the material byheating or applying a solvent. In FIG. 1 the material is softened byspraying a solvent onto the imaging material with the atomizer 9. Thematerial is softened until its cohesive strength is reduced sufficientlyso that the application of electric field combined with the action ofactinic radiation on the electrically photosensitive materials willfracture the layer upon separation of the manifold set. Further, thelayer must respond to the application of field the strengthiof which isbelow that field strength which will cause electrical breakdown orarcing across the layer. The material is softened until its cohesivestrength is less than the adhesive force between itself and either thedonor or receiver layer. The imaging material is said to be structurablyfracturable when softened the prescribed amount.

In the present invention, the receiver and donor layers are electricallyinsulating. Consequently, an electric field is established across themanifold set by contacting the receiver and donor layers withelectrically conductive electrodes between which a voltage is applied.The field can also be established by depositing charge with a corotronon one layer and backing the other layer with a grounded electrode. Thereceiver and donor layers themselves can be conductive in which casevoltage potentials could be coupled directly to them. This ispermissible because the binder 6 is normally electrically insulating.

The imaging material 3 may be exposed to electromagnetic radiationthrough either the donor or receiver layer. In FIG. 1, the arrows 10represent electromagnetic radiation being directed onto the imagingmaterial through the donor layer. When the receiver and donor layers areseparated, i.e., stripped apart, the imaging material divides betweenthe two layers. The imaging material exposed to radiation, as indicatedby arrows 10, adheres to the receiver layer and the unexposed materialadheres to the donor layer. The separation takes place while theelectric field is applied. One theory proposed to explain the divisionof the imaging material between the two abutting layers is that thephotosensitive particles 5 exposed to the radiation tend to move underthe influence of the field. The tendency to move creates stresses withinthe imaging material that alter the adhesive bond with the layer awayfrom which the particles tend to move. The cohesively weak nature of theimaging material is believed to explain why the fracture extendssubstantially the full thickness of the imaging material.

The copending application Ser. No. 609,057 fully sets forthrepresentative compounds and materials which can be used in forming themanifold imaging process. For purposes of example, the followingmaterials are representative. The donor substrate or layer and thereceiver layer may preferably consist of a suitable insulating material.Typical insulating materials include polyethylene, polyethyleneterephthalate, cellulose acetate, paper, plastic-coated paper, such aspolyethylenecoated paper, and mixtures thereof. Suitable activatingfluids, i.e., solvents, may include any material which will reduce thecohesive strength of the imaging material. Typical materials includekerosene, carbon tetrachloride, petroleum ether, silicone oils, etc. Theimaging layer may comprise any typical photoresponsive material in abinder. Typical photoresponsive material includes photoconductors suchas substituted and unsubstituted phthalocyanine; quinacridones; zincoxide, mercuric sulfide, etc. Binder materials may include insulatingresins such as polyethylene, polypropylene, etc. For more completeinformation on the above compounds and materials reference is made tothe aforementioned copending application Ser. No. 609,057.

Turning now to FIG. 2, the present imaging system includes the backingelectrode 12 and the tape electrode 13 wound on spool 14. The manifoldset includes the donor web 15 and receiver web 16 and is formed betweenthe electrodes, exposed to electromagnetic radiation, subjected to anelectric field and stripped apart to yield positive and negative images.

The backing electrode 12 is made from an optically transparent glassplate (it may be in a drum configuration) on which is deposited anoptically transparent layer of tin oxide that is electricallyconductive. Conductive glass of the type described is availablecommercially under the trade name NESA glass. The conductive layer oftin oxide is on the surface of the backing electrode closest to the tapeelectrode 13.

The tape electrode 13 is made from a conductive material that isflexible allowing it to be repeatedly coiled and uncoiled on spool 14.Preferably, the tape electrode is also elastic. An example of a suitableelastic conductive material for the use as a tape electrode is 30durometer buna-n synthetic rubber. The tape electrode is anchored at itsfree end by an appropriate fastener 17 to enable the tape electrode tobe unwound from the spool 14. The other end of the tape electrode iscoupled to the periphery of spool 14 to enable it to be wound onto thespool. The spool is forced upward against the backing electrode eitherby a hand operation or by an appropriate support means. The spool ismoved along the length of the backing electrode while maintaining anupward force on the spool to lay the tape electrode against the backingelectrode. An appropriate support means might include an angled tracksuch as the track 18 shown in FIG. 6 in which the spool axle 19 rides.Moving the spool by motor or by hand along the track 18 causes the spoolto rotate and the tape electrode to be laid out. The angle of incline ofthe track 18 relative to the ba tking electrode is selected to cause thespool to force or compress the tape electrode against the backingelectrode. The spool and its support therefore compose a compressionmeans for forcing the tape electrode against the backing electrode. Whena manifold set is between the electrodes, the compression means helpsestablish intimate contact between the various layers of the manifoldset. This aspect of the present invention is discussed again inconnection with FIG. 5.

The donor web 15 includes a donor layer on which a layer of imagingmaterial is deposited such as the layers 2 and 3 shown in FIG. 1. Theimaging material is rendered structurally fracturable (its cohesivestrength is made less than the adhesive bond betweenit and the donor orreceiver layer) by the application of a suitable solvent. Roller 20 wetsthe surface of the imaging material on the web 15 and softens it to thepoint of rendering the material structurally fracturable. The solvent ismaintained at a level in tank 21 sufiicient to coat the periphery of theroller. As the web 15 moves past the roller 20, friction forces rotateroller 20 to coat the solvent onto the surface of the web. 4

The donor web 15 is coupled between the takeup reel 23 and the storagereel 25. Appropriate drive means is coupled to the takeup reel toadvance an unused portion of web 15 to a position adjacent the backingelectrode 12. The receiver web 16 is stored on the feed reel 24. A freshportion of receiver web is advanced from reel 24 by the pinch driverollers 26 and 27. The receiver web is guided to the nip (the area ofcontact between the tape and blocking electrodes) by the guide tray 29.The spool 14 advances a short distance to trap the tip of the receiversheet between itself and the backing electrode. The spool then continuesto move from left to right (as viewed in FIG. 2) along the length of thebacking electrode laying out substantially the entire tape electrode orat least an amount sufficient to cover the area exposed to theelectromagnetic radiation. The unwindingof the tape electrode isschematically illustrated in FIG. 3.

The guide tray 29 is bent downward at point 30 to form the positive andnegative sloped ramps 31 and 32. The tray is biased by the coil spring33 such that point 30 tends to contact the backing electrode. When thespool moves left to right the spool rides on ramp 31 forcing the traydownward against the action of the spring and out of the way of thespool. The tray is once again forced downward out of the path of thespool when the spool rides on ramp 32 as it travels from the right tothe left.

As spool 14 travels from left to right unrolling the tape electrode asillustrated in FIG. 3, the receiver web 16 is pulled forward by thespool to lay the receiver sheet against the imaging material on thedonor web 15. Override clutches are coupled to the shaft of the pinchrollers 26 and 27 to allow the receiver web to be advanced by the actionof the spool 14. When the spool travels from right to left winding thetape electrode back onto the spool 14, the receiver sheet is strippedfrom the manifold set by rollers 26 and 27 which are now driven in areverse direction by appropriate drive and gear means. The winding ofthe tape electrode back onto spool 14 and the separation of the receiverweb from the manifold set is illustrated schematically in FIG. 4. Thereceiver web is separated from the manifold set at substantially thesame rate at which the spool translates. The capstan 36 is positionedsuch that the force exerted on the receiver web by the pinch rollersincludes a downward-directed force component. The vertical forcecomponent becomes smaller as the spool advances further to the leftbecause the angle between the capstan and the spool relative to thehorizon decreases. However, the position of capstan 36 is selected sothe vertical force component is sufficient to effect separation of thereceiver sheet even when the spool is at its leftmost position. Thehorizontal force component exerted on the receiver web is sufficient topull the web from the grip of the two electrodes when the spool isreturned to a position near its initial starting point. The receiver webis severed by the knife edges on cutter bars 37 and 38, falls onto theramp 32 of tray 29 and is ejected from the tray by gravity or anotherwise appropriate sheet-feeding mechanism.

The performance of the presently described manifold imaging system isimproved if the layers of the manifold set are in intimate contact. Inthe present invention, the imaging material is initially in intimatecontact with the donor layer because it is deposited thereon. On theother hand, the contact between the imaging material and the receiverlayer is depended upon the action of the present imaging apparatus. Thereceiver web is forced into contact with the imaging material layer inthe present imaging system by at least three forces: one force being themechanical force exerted by the spool against the tape electrode;another force is the electrical force established by the voltagescoupled to the electrodes; and, the third force is the force exerted byatmospheric pressure. As to the latter force, gases present between theelectrodes and the layers of the manifold set are expelled by the forceexerted by the spool against the two electrodes.

FIG. 5 is a cross section of a manifold set formed between the backingand tape electrodes. The donor web includes the donor layer 2 andimaging material 3 (the same as in FIG. 1). The width of the donor andreceiver webs are substantially the same. Preferably the width of thetape electrode is greater than either the width of the donor or receiverweb. For one, the greater width of the tape electrode allows for somemisalignment between the various layers of the manifold set and theelectrodes. In the case shown in FIG. 5, the tape electrode has a thinlayer of insulating material 39 coated on its upper surface to preventelectrical shorting between the two electrodes. The tape electrode formsa seal between the two electrodes keeping atmospheric pressure acting onthe manifold set. It should be pointed out, however, that gases areexpelled between the imaging material and receiver layers as the tapeelectrode is forced against the backing electrode. Consequently,atmospheric pressure acts to maintain intimate contact between thoselayers of the manifold set even if the width of the tape electrode isthe same or less than that of the receiver sheet.

The exposure of the manifold set to electromagnetic radiation is made byexposure means including the lamp 40, the transparency 41 and the lens42. The radiation produced by lamp 40 is selectively transmitted bytransparency 41 in imagewise configuration, is collected by lens 42 andprojected through the transparent donor layer to the imaging material.The electric field used in the imaging system is established by anappropriate voltage source 43 coupled at one terminal to the tapeelectrode 13 and at a second terminal to a ground potential 44 and theground potential 44 coupled to the backing electrode 12.

After images are formed on the donor and receiver webs, the donor web istacked by electrostatic and other forces to the backing electrode. Thedonor web is separated form the backing electrode by running a knifeedge between the, puffing air between them, raising the backingelectrode or by other appropriate means. Thereafter the used donor webis wound onto takeup reel 23 bringing a new portion of web 15 adjacentthe backing electrode. A new section of the receiver web is advanced tothe nip between the two electrodes and the aforedescribed operation isrepeated to form another image.

What is claimed is:

1. Imaging apparatus comprising backing electrode and a conductiveelastic tape electrode having means for coupling to a volta e source toestablish an electric field between them an to attract the tapeelectrode by electrical force toward the backing electrode,

5 compression means for forcing the tape electrode toward the backingelectrode to form a structurably fracturable manifold set from a donorlayer, an imaging material layer and a receiver layer positioned betweenthe electrodes, and

exposure means for exposing the imaging material of a manifold set toelectromagnetic radiation whereby the adhesive attraction between theimaging layer and donor and receiver layers is altered in areas exposedto radiation and subjected to electric field.

2. The apparatus of claim 1 further including means to weaken thecohesive strength of an imaging layer placed between said electrodes.

3. The apparatus of claim 1 wherein said backing electrode includes atransparent material for transmitting electromagnetic radiation to atransparent donor layer and an imaging layer.

4. The apparatus of claim 1 further including stripping means toseparate the tape and backing electrodes and the receiver and donorlayer to fracture an imaging layer between the electrodes in areasexposed to radiation and field yielding complementary images on saiddonor and receiver layers.

5. The apparatus of claim 4 wherein said stripping means in-' cludesmeans to restrain the donor layer and backing electrode and to separatethe tape electrode and receiver layer from the backing electrode anddonor layer.

6. The apparatus of claim 5 further including means to separate adonor-layer from said backing electrode after an imaging layer has beenfractured.

7. The apparatus of claim 1 wherein said compression means includes aspool member supported for travel relative to said electrodes and forforcing one electrode against the other during its travel driving outgases between the electrodes.

8. The apparatus of claim 1 further including a spool to which one endof said tape electrode is coupled for winding the electrode on the spoolwith the free end of the tape electrode anchored to facilitate unwindingof the tape electrode'from the spool, and

means to support and rotate said spool to wind and unwind the tapeelectrode adjacent the backing electrode and to force the spool towardthe backing electrode.

9. The apparatus of claim 8 further including means exerting a force onthe receiver layer for separating the receiver layer from the tapeelectrode and a donor layer as the tape 50 electrode is wound onto saidspool.

10. The apparatus of claim 8 further including first feed means forpositioning adjacent the backing electrode a donor layer having animaging layer deposited thereon; and

second feed means for positioning a receiver layer adjacent the imaginglayer before the tape electrode is unwound from the spool whereby thecompression means and electrical field forces the receiver layer intocontact with the imaging layer as the tape electrode is unwound from thespool.

11. The apparatus of claim 10 wherein said second feed means includes adrive means for advancing a layer adjacent said electrodes while thetape electrode is wound on the spool. for allowing the layer to beadvanced by the spool to compress 5 the web between the electrodes andfor withdrawing the web from the electrodes as the tape electrode iswound onto the spool.

12. The apparatus of claim 11 further including a tray biased to contactthe backing electrode when the tape elec- 70 trode is wound on the spoolto guide a web to a position adjacent the path traveled by the spool andto support the web after its separation from the electrodes.

llun'n need

1. Imaging apparatus comprising backing electrode and a conductiveelastic tape electrode having means for coupling to a voltage source toestablish an electric field between them and to attract the tapeelectrode by electrical force toward the backing electrode, compressionmeans for forcing the tape electrode toward the backing electrode toform a structurably fracturable manifold set from a donor layer, animaging material layer and a receiver layer positioned between theelectrodes, and exposure means for exposing the imaging material of amanifold set to electromagnetic radiation whereby the adhesiveattraction between the imaging layer and donor and receiver layers isaltered in areas exposed to radiation and subjected to electric field.2. The apparatus of claim 1 further including means to weaken thecohesive strength of an imaging layer placed between said electrodes. 3.The apparatus of claim 1 wherein said backing electrode includes atransparent material for transmitting electromagnetic radiation to atransparent donor layer and an imaging layer.
 4. The apparatus of claim1 further including stripping means to separate the tape and backingelectrodes and the receiver and donor layer to fracture an imaging layerbetween the electrodes in areas exposed to radiation and field yieldingcomplementary images on said donor and receiver layers.
 5. The apparatusof claim 4 wherein said stripping means includes means to restrain thedonor layer and backing electrode and to separate the tape electrode andreceiver layer from the backing electrode and donor layer.
 6. Theapparatus of claim 5 further including means to separate a donor layerfrom said backing electrode after an imaging layer has been fractured.7. The apparatus of claim 1 wherein said compression means includes aspool member supported for travel relative to said electrodes and forforcing one electrode against the other during its travel driving outgases between the electrodes.
 8. The apparatus of claim 1 furtherincluding a spool to which one end of said tape electrode is coupled forwinding the electrode on the spool with the free end of the tapeelectrode anchored to facilitate unwinding of the tape electrode fromthe spool, and means to support and roTate said spool to wind and unwindthe tape electrode adjacent the backing electrode and to force the spooltoward the backing electrode.
 9. The apparatus of claim 8 furtherincluding means exerting a force on the receiver layer for separatingthe receiver layer from the tape electrode and a donor layer as the tapeelectrode is wound onto said spool.
 10. The apparatus of claim 8 furtherincluding first feed means for positioning adjacent the backingelectrode a donor layer having an imaging layer deposited thereon; andsecond feed means for positioning a receiver layer adjacent the imaginglayer before the tape electrode is unwound from the spool whereby thecompression means and electrical field forces the receiver layer intocontact with the imaging layer as the tape electrode is unwound from thespool.
 11. The apparatus of claim 10 wherein said second feed meansincludes a drive means for advancing a layer adjacent said electrodeswhile the tape electrode is wound on the spool, for allowing the layerto be advanced by the spool to compress the web between the electrodesand for withdrawing the web from the electrodes as the tape electrode iswound onto the spool.
 12. The apparatus of claim 11 further including atray biased to contact the backing electrode when the tape electrode iswound on the spool to guide a web to a position adjacent the pathtraveled by the spool and to support the web after its separation fromthe electrodes.